Jejunal obstruction

Di Lorenzo C, Flores AF, Buie T, Hyman PE Intestinal motility and jejunal feeding in children with chronic intestinal pseudo-obstruction. Gastroenterology 1995 108 1379-1385. 

Summers RW, Anuras S, Green J Jejunal manometry patterns in health, partial intestinal obstruction, and pseudoobstruction. Gastroenterology 1983 85 1290-1300. 

These external neural influences on intestinal motility are common targets for prokinetic drugs, but events within the bowel can have important effects on intestinal motility and cause the bowel to be refractory to traditional prokinetic therapy. Release of cytokines from activated inflammatory cells is probably an important feature of ileus in many cases. Ileus secondary to reperfusion injury is an anticipated response in horses with small intestinal obstruction. However, even apparently mild intestinal injury can initiate cellular responses that lead to impaired motility. Mild intestinal insult by gentle surgical manipulation activated adhesion molecules on leukocytes and increased the expression of P-selectin and intercellular adhesion molecule 1 on endothelial cells within the vasculature of the muscularis layer of the intestine (Kalff et al 1999). Surgical manipulation of the rodent small intestine resulted in substantial extravasation of leukocytes into the intestinal muscularis, consisting mainly of polymorphonuclear neutrophils, monocytes and mast cells and lasting for days. This cellular inflammatory response within the intestinal muscularis externa was associated with a marked decrease in jejunal circular muscle activity (Kalff et al 1998). 

Jejunal atresias comprise approximately 50% of small bowel atresias, and in 10% of the cases, there are multiple areas of atresia (De Lorimier et al. 1969). Jejunal atresia is clinically characterized by bilious vomiting, frequently delayed until after the first feeding, and abdominal distension. The lower the obstructive lesion in the small bowel, the more severe the abdominal distension, and the more difficult the accurate localization of the site of obstruction is (Godbole and Stringer 2002). 

Fig. 1.14a,b. Jejunal atresia, a Supine radiograph shows a few dilated, air-filled intestinal loops, about four bubbles , which indicates a high obstruction, b Surgical image demonstrates the location of the atresia (arrow), the dilated proximal jejunum, and the small caliber of the bowel distal to the atresia... 

Fig. 1.15a,b. Jejunal atresia. Anteroposterior (a) and lateral (b) upright radiographs show a few central air-lluid levels indicating high obstruction... 

Fig. 1.16a,b. Jejunal atresia, a Supine radiograph shows an airless abdomen, b Aspiration and insufflation of air through a nasogastric tube was performed and adequately demonstrates the point of obstruction (arrow). Massively dilated loops of jejunum but only about three bubbles give indication of a high obstruction... 

Ileal atresia is an important cause for low intestinal obstruction. It represents approximately 50% of small bowel atresias and the etiology is similar to that of jejunal atresia. As jejunal atresias, they are believed to result from an intrauterine vascular injury. Approximately 25% have a history of polyhydramnios (Sweeney et al. 2001). 

Duodenal Obstruction 170 Jejunal and Ileal Obstruction 172 Meconium Peritonitis 173 Meconium Ileus 173 Megacystis-Microcolon-Malrotation-Intestinal-Hypoperistalsis Syndrome (MMMIHS) 174... 

Neonates with jejunal or ileal obstruction may also present with bilious vomiting depending on the level (most likely proximal) of obstruction. This clinical symptom is usually less severe than in duodenal obstruction. 

The radiological diagnosis of obstruction is usually visible on the conventional (plain) radiograph. In uncomplicated cases these radiographs of the abdomen are sufficient. The pre-atretic intestinal loops are dilated because of accumulation of large amounts of fluid and fluid levels are usually present on horizontal beam films. In case of jejunal atresia only a few loops of distended jejunum are present in the left upper abdomen, while in ileal atresia many dilated loops are identified. In complicated cases, especially with an abnormally distended and painful abdomen, a colon enema or US can be useful- particularly from the differential diagnostic point of view to exclude meconium ileus or meconium peritonitis. In case of atresia, a microcolon without the presence of meconium is usually found (Devos and Meradji 2003). 

Summers, R.W., Anuras, S., and Green, 1. 1982. jejunal motility patterns in normal subjects and symptomatic patients with partial mechanical obstruction or pseudo-obstruction. In Motility of the Digestive Tract, Weinbeck, M. (Ed.), Raven Press, New York, pp. 467-470. 

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